One of the mathematical problems that Charles Dodgson probably WASN'T asked to elucidate during his tenure as Lecturer in Mathematics at Christ Church College, Oxford:
Q: What do you get if you take a rather creepy paedophile who possessed the saving grace of having written some of the most fascinatingly quirky and playfully profound texts in the English language and subtract from him the saving grace of having written some of the most fascinatingly quirky and playfully profound texts in the English language?
A: A rather creepy paedophile.